Hydraulically damped assembly bearings are generally known from, for example, DE 39 33 252 C2. In essence, the known assembly bearing is provided with a hydraulic chamber divided by a dividing wall into a working chamber and a compensation chamber. In the dividing wall is disposed a damping channel which interconnects the two chambers and permits a fluid to flow through.
The working chamber is limited at the top by a spring body that essentially has the shape of a truncated cone and is made of an elastic rubber material with a vulcanized connecting piece. The working chamber is limited at the bottom by a compensation membrane capable of taking up volume without pressure and which is covered by a bearing cap provided with fastening means. In addition, an overflow gap is provided in the compensation chamber, the opening cross-section of which can be variably adjusted from the outside.
The opening gap is formed by an axially displaceable, conical lowering plate in the compensation chamber, and is provided with breaches and a corresponding conical counter-surface which is fitted to an intermediate part. In this manner, a quenching effect variable in frequency is achieved, wherein the effect is intended to result in a frequency-dependent, regulatable acoustic abatement.
The known assembly bearing has a drawback, however, that because of the inertia of the liquid column in the damping channel compared to the higher-frequency and high-frequency low-amplitude excitation, these vibrations are not transmitted to the compensation chamber. As a result, the desired quenching does not take effect, or insufficiently takes effect.